The ruble hits 7-month low versus the dollar as sanctions and trade restrictions weigh on Russia's currency

• The Russian ruble has fallen to about 71 versus the dollar, a seven-month low against the greenback.
• That's a sign that the latest western sanctions, including a price cap on Russian oil, are weighing on the Russia's currency.
• The ruble has declined 12% since the oil price cap kicked into effect as Russian crude exports tumble.

The ruble just hit a seven-month low against the dollar, a sign that western sanctions are biting into Russia's economy and are weighing on its currency.

The ruble fell 2.5% on Wednesday morning to 70.60 versus the dollar. It's the cheapest level the ruble has been valued since May, around the time Russia first started propping up its currency against headwinds from western sanctions.

That intervention led the ruble to be the world's top-performing currency at the time, though it's now been surpassed by the Brazilian real. The fall has mostly stemmed from the latest round of sanctions against Russia, with the European Union banning on Russian oil earlier this month and slapping a $60 price cap on Russian crude.

Russia has refused to abide by the price cap and threatened retaliation against any country that follows it, with Russian President Vladimir Putin calling the mechanism "stupid." He assured citizens in a recent speech that Russia's economy was resilient.

Oil and gas are among Russia's key revenue streams, and it's proving difficult for Russia to replace Europe as a customer. Russian crude exports cratered 54% the first week of the oil ban, and Russia's central bank warned that the new sanctions were "economic shocks."

Some of Russia's allies are also bartering for steeper discounts with the price cap in place. Some shipments of crude headed to China are being sold as low as $68 a barrel, and some shipments headed to India are being sold below the price cap, reports say.

So far, Russian oil exports have fallen off 11% this month compared to November, according to Russian news outlet Kommersant. Meanwhile, the ruble has fallen 12% since the price cap was put in place, Reuters reported.